Method and means for upsetting sheet metal



METHOD AND' MEANS FOR UPSETTING SHEET IETAL June 3, 1930.

Filed Aug. 3, 1925 2 Sheets-sheet 1- June 3, 1930. H. JUNKERS 1,761,887

METHOD AND MEANS FOR UPSETTING SHEET METAL Filed fiz- 1925 2 Sheets-Sheet 2 Patented June 3, 1930 I 1 HUGO TUNKERS, OF DESSA'U, GERMANY ME'I'H OD AND MEAN S FOR UPSE'ITING SHE E'I METAL Application filed August 3, 1925, Serial No. 47,816, and in Germany August 15, 1924.

My invention refers to sheet metal shapes (which expression is meant to com rise also endless sheet metal strips, bands, s (acts and the like) and it concerns more particularly the distribution'of metal in such' shapes and the manner of changing the distribution of metal and at thesame time also, the configuration' of the shape. It is a particular obtion of narrow sheet metal strips by reducing or increasing thelength without producing folds in the metal. v

According to the present invention thi change of configuration is brought about by means of. a device comprising two pairs of gripping aws, the jaws of each pair of jaws being arranged to be pressed against each other so as to grip part of the metal and the pairs being arranged to be then moved to- 20 wards oraway from each other so as, to upset or stretchthe piece of sheet metal enclosed between them. In consequence of this mode of proceeding the strength of the material is not impaired and owing to the fact that the upsetting results in an accumulation,

of metal incertain parts of the strip or other shape thus acted upon certain parts can even be made stronger by this method.

In applying this invention to particular ly thin sheet metal I'prefer using pairs ofjaws in which the jaws disposed on the same side of the shet metal shape are formed with interlocking projections resembling combs, wherebythese jaws are enabled to prevent the sheet metal from iving way during the upsetting operation. 11 this manner the formation of folds is -rendered'impossible even in the case of very thin sheet metal.

-'In the drawings-afiixed to this specificapart thereof several forms tion and forming ying my. mventronare illusof a device embo trated diagrammatically by way of example.- a In the drawings Fig.1 is a erspective view of two cooper ating pairs '0 motion. h

Figs. 2-4 illustrate a special kind of grip: ping jaws and means for operatin jaws arranged for rectilinear jaws in position in the press before the upsettical arrow 6. The two pairs of projectin same, Fig. 2 being a vertical section showing the ting operation. Fig. 3 is a. plan view of one of the jaws, and Fig. 4 is a perspective view.

jaws aving an undulated gripping sur ace. ject of my invention to change the configura- Fig. 8 is a vertical section showing a pair of jaws, one of which has a plane, the, other a curved grip ing surface.

Referring rst to Fig. 1, 1, 2 is a pair of jaws which can be moved or forced towards each other inthe direction of the vertical arrow 3 in order to forcibly hold a piece of sheet 66 metal between them. I

4,. 5 is another pair of jawscapable of relative'movement in the direction of the verjaws are further adapted to be displaced re ative to each other in the direction of the horizontal arrows 7 and 8, so as to upset a sheet'metal piece held between them. In order'to prevent the work piece from (giving way side- .ways, whereby folds woul be ormed, the. jaws are formed with tooth-like extensions 9 and 10,.the extensions of one pair of jaws intothe gaps between the exten sions' of t e other palr, and the abutting surfaces of these extensions bein very slightly recessed in order to prevent fiieir clamping I between them that portion of the workpiece which shallbe upset, such upsettin being accompanied by anaccumulation 0 'metal in the upset portion. In the drawing the depth of these recesses is greatly. exaggerated for. the sake of clearness and in reality the recesses-are very shallow.

In the modification illustrated in Figs. 2-4

the jaws 51, 52, 53, 5a havecam faces 56 on the side opposite the gri ping face and the parts 57, 58 of the mem rs, which are in ,4 contact with the jaws have corresponding cam faces, springs 59 or the like inserted between the jaws serving to keep these latter in inoperative osition; .Whenever pressure cam faces cause the-jaws to move towards each other. While the vertical forces cause the work piece to be tightly gripped between 10 "isexerted on the press members 57, 58 the rection are arranged to slope inwardly, the

, horizontal forces resulting on. vertical pressure acting'on-the members 57 58 will act towards forcing the pairs of jaws outwards, whereby the work piece will be stretched.

m The arrangement of cam faces on the jaws and press members as above described ;in-

' volves the advantage that the gripping and upsetting or stretchin of the work piece is effected in one and t e same operation, s0

- thatit is possible to carry out this'operation by means of any ordinary pressin tool, such as a vise, a spindle press or the li e. I may, however, also operate these jaws by. mechane. .icalmeansQ I may further arrange the jaws in such manner that the work piece can be deformed simultaneously in several places. An arrangement of thiskindxis shown in Figs. 5 r and 6, where pairs of jaws of the kind illusat. trated in Figs. 24ers arranged in a spindle v in a piece of sheet metal comprising two pairs press 60 in such manner that the work piece 61 bent into tl' shape can be acted upon simultaneously at its two flanges 62, 63, the pair ofjaws being superposed in the modification illustrated in the drawing and an intermediateblock 68 being inserted between them,

both this block and the jaws being suitably guided in guides 69 in such manner that they can move in the direction of pressure and are prevented from giving way sideways."

Obviously the gripping faces of the jaws need not be plainbut may be shaped as desired, to allowgripping also, work pieces of irregular shape or work pieces curved in two ac directions. The jaws illustrated in Fig. 7 are formed with undulated surfaces to grip corrugated sheet metal strips. The pairs of jaws J shown inFig. 8 differ in the configuration of their gripping surfaces, the upper jaws having a spherical surface while the bottom 'aws have a plain surface, so that metal s eet curved in different directions can be subjected to upsetting or stretchingoperationa Jaws of a similar kind will allow carrying 5 out chasing or embossing operations cf all kinds. I wish it to be understood that I- do not desire to be limited to any details of configuration, operation andconstruction shown and described for obvious m'odifications will occur Q to a person skilled in the art.

Iclaim:.- v Q 1. Device for producing a change of form n a piece of sheet metal comprising two pairs of gripping jaws movable towards and away from each other and extensions on opposite in a piece of sheet metal comprising two pairs of gripping jaws movable towards and away from each other, means connected with said pairs of jaws for preventing bending or foldmg of the sheet metal during such movement and a single means for first closing the jaws 3. Device, for vproducing a change of form in a piece of sheet metal comprising two pairs.

of gripping jaws movable towards and away from each other, converging cam faceson the surface ofthe jaws opposite the gripping surface, pressure exerting means and correof each pair and thereafter moving said pairs of aws relative to one another.

for resihently vcounteracting relative motion of said pairs of jaws. '5. Device for producing a change of form of gripping jaws movable towards and away from each other, converging cam faces on the surface of the jaws opposite the gripping 'surface, pressure exerting means, corresponding "cam faces on said means and springs mserted between said jaws for resiliently counteracting horizontal motion of said jaws towards each other. e

6. Device for p'roducing a change of form in a piece of sheet metal comprising several pressure on the jaws constituting such units and corresponding cam faces on said means.

units of gripping jaws, each unit comprising in series, means for simultaneously exerting In testimony whereof I afiix my signature.

HUGO JUNKERS.

edges of said pairs of jaws, the extensions of 7 .one pair of jaws projectin into the gap separatin the extensions'of t 0 other pair.

2. evice for producingachange of form 

